Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

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In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class KarenAndGame815A {

    public static Map<Integer, Integer> row(int n, int m, int a[][]) {
        int i = 0;

        Map<Integer, Integer> mr = new HashMap<>();
        while (i < n) {
            int M = Integer.MAX_VALUE;
            int rc = 0;
            for (int k = 0; k < m; k++) {
                if (a[i][k] > 0) {
                    M = Math.min(M, a[i][k]);
                    rc++;
                } else {
                    i++;
                    break;
                }
            }
            if (rc == m) {
                for (int k = 0; k < m; k++) {
                    a[i][k] -= M;
                }
                mr.put(i, M);

            }
        }
        return mr;
    }

    public static Map<Integer, Integer> col(int n, int m, int a[][]) {

        int j = 0;

        Map<Integer, Integer> mc = new HashMap<>();
        while (j < m) {
            int M = Integer.MAX_VALUE;
            int rc = 0;
            for (int k = 0; k < n; k++) {
                if (a[k][j] > 0) {
                    M = Math.min(M, a[k][j]);
                    rc++;
                } else {
                    j++;
                    break;
                }
            }
            if (rc == n) {
                for (int k = 0; k < n; k++) {
                    a[k][j] -= M;
                }
                mc.put(j, M);

            }
        }
        return mc;
    }

    public static void main(String[] args) throws IOException {
        int n = gi();
        int m = gi();
        int a[][] = new int[n][m];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                a[i][j] = gi();
            }
        }

        // System.out.println(Arrays.deepToString(a));
        ///////
        Map<Integer, Integer> mr;
        Map<Integer, Integer> mc;
        if (m < n) {
            mc = col(n, m, a);
            mr = row(n, m, a);
        } else {
            mr = row(n, m, a);
            mc = col(n, m, a);
        }

        // System.out.println(Arrays.deepToString(a));
        int ccc = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (a[i][j] > 0) {
                    ++ccc;
                }
            }
        }
        if (ccc > 0) {
            System.out.println(-1);
        } else {
            int cp = 0;
            for (Map.Entry<Integer, Integer> e : mr.entrySet()) {
                cp += e.getValue();
            }
            for (Map.Entry<Integer, Integer> e : mc.entrySet()) {
                cp += e.getValue();
            }
            System.out.println(cp);
            for (Map.Entry<Integer, Integer> e : mr.entrySet()) {
                int kp = e.getValue();
                while (kp > 0) {
                    System.out.println("row " + (e.getKey() + 1));
                    kp--;
                }
            }
            for (Map.Entry<Integer, Integer> e : mc.entrySet()) {
                int kp = e.getValue();
                while (kp > 0) {
                    System.out.println("col " + (e.getKey() + 1));
                    kp--;
                }
            }

            // System.out.println(mr + " " + mc);

        }

    }

    public static BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in), 32768);
    public static StringTokenizer stringTokenizer = null;

    public static int gi() throws IOException {

        return Integer.parseInt(next());
    }

    public static long gl() throws IOException {
        return Long.parseLong(next());
    }

    public static double gd() throws IOException {
        return Double.parseDouble(next());
    }

    public static String gs() throws IOException {
        return next();
    }

    public static char gc() throws IOException {
        return next().charAt(0);
    }

    public static String next() {
        while (stringTokenizer == null || !stringTokenizer.hasMoreTokens()) {
            try {
                stringTokenizer = new StringTokenizer(bufferedReader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return stringTokenizer.nextToken();
    }

    public static StringBuilder ap(String str) {
        answerStringBuilder.append(str);
        return answerStringBuilder;
    }

    public static StringBuilder answerStringBuilder = new StringBuilder();

}